U.S. patent number 11,067,303 [Application Number 16/461,402] was granted by the patent office on 2021-07-20 for air-conditioning apparatus.
This patent grant is currently assigned to Mitsubishi Electric Corporation. The grantee listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Koichi Obara, Yasuhiro Suzuki, Masahiko Takagi, Kenyu Tanaka, Kazuki Watanabe.
United States Patent |
11,067,303 |
Obara , et al. |
July 20, 2021 |
Air-conditioning apparatus
Abstract
An air-conditioning apparatus includes a refrigerant circuit in
which refrigerant is circulated, and an indoor unit configured to
accommodate a load-side heat exchanger of the refrigerant circuit.
The indoor unit includes an air outlet provided in the housing, an
air inlet provided in the housing below the air outlet, an air
passage that extends between the air inlet and the air outlet via
the load-side heat exchanger, a refrigerant detection unit disposed
below the air inlet, and a first partition plate configured to
separate the air passage from a space in which the refrigerant
detection unit is installed.
Inventors: |
Obara; Koichi (Tokyo,
JP), Takagi; Masahiko (Tokyo, JP), Suzuki;
Yasuhiro (Tokyo, JP), Tanaka; Kenyu (Tokyo,
JP), Watanabe; Kazuki (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
N/A |
JP |
|
|
Assignee: |
Mitsubishi Electric Corporation
(Tokyo, JP)
|
Family
ID: |
1000005690278 |
Appl.
No.: |
16/461,402 |
Filed: |
February 1, 2017 |
PCT
Filed: |
February 01, 2017 |
PCT No.: |
PCT/JP2017/003611 |
371(c)(1),(2),(4) Date: |
May 16, 2019 |
PCT
Pub. No.: |
WO2018/142509 |
PCT
Pub. Date: |
August 09, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190346165 A1 |
Nov 14, 2019 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F
11/89 (20180101); F24F 11/36 (20180101); F24F
13/20 (20130101) |
Current International
Class: |
F24F
11/36 (20180101); F24F 11/89 (20180101); F24F
13/20 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
204648457 |
|
Sep 2015 |
|
CN |
|
2679921 |
|
Jan 2014 |
|
EP |
|
S63-27859 |
|
Feb 1988 |
|
JP |
|
H08-06172 |
|
Mar 1996 |
|
JP |
|
H08-61702 |
|
Mar 1996 |
|
JP |
|
2990570 |
|
Dec 1999 |
|
JP |
|
2002-098346 |
|
Apr 2002 |
|
JP |
|
2005-049004 |
|
Feb 2005 |
|
JP |
|
2005-049004 |
|
Feb 2005 |
|
JP |
|
4599699 |
|
Dec 2010 |
|
JP |
|
2011-092751 |
|
May 2011 |
|
JP |
|
2016/151642 |
|
Sep 2016 |
|
WO |
|
Other References
Office Action dated Jun. 2, 2020 issued in corresponding JP patent
application No. 2018-565141 (and English translation). cited by
applicant .
Office Action dated Jul. 3, 2020 issued in corresponding CN patent
application No. 201780084693.9 (and English translation). cited by
applicant .
Examination Report dated Nov. 21, 2019 issued in corresponding AU
patent application No. 2017396590. cited by applicant .
Extended European Search Report dated Dec. 17, 2019 issued in
corresponding EP patent application No. 17894703.2. cited by
applicant .
International Search Report of the International Searching
Authority dated Apr. 4, 2017 for the corresponding international
application No. PCT/JP2017/003611 (and English translation). cited
by applicant .
European Office Action dated May 4, 2021, issued in corresponding
European Patent Application No. 17894703.2. cited by applicant
.
Chinese Office Action dated May 26, 2021, issued in corresponding
CN Patent Application No. 201780084693.9 (and English translation).
cited by applicant.
|
Primary Examiner: Crenshaw; Henry T
Attorney, Agent or Firm: Posz Law Group, PLC
Claims
What is claimed is:
1. An air-conditioning apparatus comprising: a refrigerant circuit
configured to circulate refrigerant between an indoor unit and an
outdoor unit; and the indoor unit including a load-side heat
exchanger of the refrigerant circuit, wherein the indoor unit
includes: an air outlet provided in a housing, an air inlet
provided in the housing below the air outlet and below the
load-side heat exchanger, an air passage extending between the air
inlet and the air outlet via the load-side heat exchanger, a drain
pan disposed below the load-side heat exchanger and above the air
inlet, a refrigerant detection unit disposed below the air inlet,
and a first partition plate configured to separate the air passage
from a space in which the refrigerant detection unit is installed,
and wherein the space is configured to accumulate leaked
refrigerant.
2. The air-conditioning apparatus of claim 1, wherein the indoor
unit further includes a fan casing configured to accommodate a fan,
wherein an air inlet opening of the fan casing is positioned so as
to face the air inlet, and wherein the first partition plate
separates a space within the air passage between the air inlet and
the fan casing from the space in which the refrigerant detection
unit is installed.
3. The air-conditioning apparatus of claim 1, wherein a refrigerant
pipe connected to the load-side heat exchanger is disposed inside
the housing beside the air passage, and wherein the first partition
plate is not provided directly below the refrigerant pipe.
4. The air-conditioning apparatus of claim 3, wherein the indoor
unit further includes a second partition plate configured to
separate the air passage from a space in which the refrigerant pipe
is installed.
5. The air-conditioning apparatus of claim 1, wherein a particulate
adsorbing element is disposed on a surface of the first partition
plate adjacent to the air passage.
6. The air-conditioning apparatus of claim 1, wherein the first
partition plate has a structure which is separate from the drain
pan.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application is a U.S. national stage application of
PCT/JP2017/003611 filed on Feb. 1, 2017, the contents of which are
incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an air-conditioning apparatus
including a refrigerant detection unit configured to detect
refrigerant leakage.
BACKGROUND ART
Patent Literature 1 describes an indoor unit of an air-conditioning
apparatus. The indoor unit includes a heat exchange chamber, and a
machine chamber. A heat exchanger through which flammable
refrigerant flows is disposed in the heat exchange chamber. A drain
pan is disposed in a lower portion of the heat exchange chamber to
receive and drain away condensed water generated in the heat
exchanger. The drain pan extends from the lower portion of the heat
exchange chamber toward a lower portion of the machine chamber. A
sensor for detecting flammable refrigerant is disposed in a lower
portion of the machine chamber near the drain pan. If flammable
refrigerant leaks out of the heat exchanger, the flammable
refrigerant flows on and along the drain pan to a lower portion of
the machine chamber, and is detected by the sensor. In response to
the detection of leakage of the flammable refrigerant, an
air-sending device of the indoor unit is activated.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 2002-98346
SUMMARY OF INVENTION
Technical Problem
Unfortunately, gas sensors used to detect refrigerant leakage often
falsely detect foreign gas (gas other than refrigerant gas) such as
propane or insecticide sucked into the indoor unit from outside of
the indoor unit.
The present invention has been made in view of the above-mentioned
problem, and an object thereof is to provide an air-conditioning
apparatus that makes it possible to prevent false detection of
foreign gas other than refrigerant.
Solution to Problem
An air-conditioning apparatus according to an embodiment of the
present invention includes a refrigerant circuit in which
refrigerant is circulated, and an indoor unit configured to
accommodate a load-side heat exchanger of the refrigerant circuit.
The indoor unit includes an air outlet provided in the housing, an
air inlet provided in the housing below the air outlet, an air
passage that extends between the air inlet and the air outlet via
the load-side heat exchanger, a refrigerant detection unit disposed
below the air inlet, and a first partition plate configured to
separate the air passage from a space in which the refrigerant
detection unit is installed.
Advantageous Effects of Invention
According to an embodiment of the present invention, the presence
of the first partition plate ensures that foreign gas sucked in
through the air inlet does not enter the space where the
refrigerant detection unit is installed. This makes it possible to
prevent false detection of the foreign gas by the refrigerant
detection unit.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a refrigerant circuit diagram illustrating the schematic
configuration of an air-conditioning apparatus according to
Embodiment 1 of the present invention.
FIG. 2 is a front view of an indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1 of the present invention,
illustrating the outward appearance of the indoor unit 1.
FIG. 3 is a front view of the indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1 of the present invention,
schematically illustrating the internal structure of the indoor
unit 1.
FIG. 4 is a side view of the indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1 of the present invention,
schematically illustrating the internal structure of the indoor
unit 1.
FIG. 5 is a side view of the indoor unit 1 of an air-conditioning
apparatus according to Embodiment 2 of the present invention,
schematically illustrating the internal structure of the indoor
unit 1.
FIG. 6 is a front view of the indoor unit 1 of an air-conditioning
apparatus according to Embodiment 3 of the present invention,
schematically illustrating the internal structure of the indoor
unit 1.
DESCRIPTION OF EMBODIMENTS
Embodiment 1
An air-conditioning apparatus according to Embodiment 1 of the
present invention will be described below. FIG. 1 is a refrigerant
circuit diagram illustrating the general configuration of an
air-conditioning apparatus according to Embodiment 1. In the
drawings described above including FIG. 1, the relative sizes of
components and their shapes may often differ from the actual
ones.
As illustrated in FIG. 1, the air-conditioning apparatus includes a
refrigerant circuit 40 in which refrigerant is circulated. The
refrigerant circuit 40 includes the following components
sequentially connected in a loop by refrigerant pipes: a compressor
3, a refrigerant flow switching device 4, a heat source-side heat
exchanger 5 (e.g. an outdoor heat exchanger), a pressure reducing
device 6, and a load-side heat exchanger 7 (e.g. an indoor heat
exchanger). The air-conditioning apparatus includes, as a heat
source unit, an outdoor unit 2 that is installed outdoors, for
example. Further, the air-conditioning apparatus includes, as a
load unit, an indoor unit 1 that is installed indoors, for example.
The indoor unit 1 and the outdoor unit 2 are connected to each
other by an extension pipe 10a (gas pipe) and an extension pipe 10b
(liquid pipe), which each constitute a portion of a refrigerant
pipe.
Examples of refrigerants circulated in the refrigerant circuit 40
include a mildly flammable refrigerant such as HFO-1234yf or
HFO-1234ze, and a highly flammable refrigerant such as R290 or
R1270. Each of these refrigerants may be used as a single-component
refrigerant, or may be used as a mixture of two or more types of
refrigerant. Hereinafter, a refrigerant with a level of
flammability equal to or higher than mild flammability (e.g. 2 L or
higher in accordance with the ASHRAE-34 classification) will be
often referred to as "flammable refrigerant". Alternatively, a
non-flammable refrigerant with no flammability (e.g. "1" in
accordance with the ASHRAE-34 classification), such as R22 or
R410A, may be used as the refrigerant to be circulated in the
refrigerant circuit 40. The above-mentioned refrigerants have, for
example, densities greater than the density of air under
atmospheric pressure.
The compressor 3 is a piece of fluid machinery that compresses a
low-pressure refrigerant sucked into the compressor 3, and
discharges the compressed refrigerant as a high-pressure
refrigerant. The refrigerant flow switching device 4 switches the
directions of refrigerant flow within the refrigerant circuit 40
between cooling operation and heating operation. As an example of
the refrigerant flow switching device 4, a four-way valve is used.
The heat source-side heat exchanger 5 acts as a radiator (e.g. a
condenser) in cooling operation, and acts as an evaporator in
heating operation. The heat source-side heat exchanger 5 exchanges
heat between the refrigerant flowing in the heat source-side heat
exchanger 5 and the outdoor air being supplied by an outdoor fan 5f
described later. The pressure reducing device 6 causes a
high-pressure refrigerant to be reduced in pressure and change to a
low-pressure refrigerant. As an example of the pressure reducing
device 6, an electronic expansion valve with an adjustable opening
degree is used. The load-side heat exchanger 7 acts as an
evaporator in cooling operation, and acts as a radiator (e.g. a
condenser) in heating operation. The load-side heat exchanger 7
exchanges heat between the refrigerant flowing in the load-side
heat exchanger 7 and the air being supplied by an indoor fan 7f
described later. In this regard, cooling operation refers to an
operation in which a low-temperature, low-pressure refrigerant is
supplied to the load-side heat exchanger 7, and heating operation
refers to an operation in which a high-temperature, high-pressure
refrigerant is supplied to the load-side heat exchanger 7.
The outdoor unit 2 accommodates the compressor 3, the refrigerant
flow switching device 4, the heat source-side heat exchanger 5, and
the pressure reducing device 6. The outdoor unit 2 also
accommodates the outdoor fan 5f that supplies outdoor air to the
heat source-side heat exchanger 5. The outdoor fan 5f is installed
so as to face the heat source-side heat exchanger 5. Rotating the
outdoor fan 5f creates a flow of air that passes through the heat
source-side heat exchanger 5. As the outdoor fan 5f, a propeller
fan is used, for example. The outdoor fan 5f is disposed, for
example, downstream of the heat source-side heat exchanger 5
relative to the flow of air created by the outdoor fan 5f.
Refrigerant pipes disposed in the outdoor unit 2 include a
refrigerant pipe connecting an extension-pipe connection valve 13a
with the refrigerant flow switching device 4 and serving as a
gas-side refrigerant pipe during cooling operation, a suction pipe
11 connected to the suction side of the compressor 3, a discharge
pipe 12 connected to the discharge side of the compressor 3, a
refrigerant pipe connecting the refrigerant flow switching device 4
with the heat source-side heat exchanger 5, a refrigerant pipe
connecting the heat source-side heat exchanger 5 with the pressure
reducing device 6, and a refrigerant pipe connecting an
extension-pipe connection valve 13b with the pressure reducing
device 6 and serving as a liquid-side refrigerant pipe during
cooling operation. The extension-pipe connection valve 13a is
implemented as a two-way valve capable of being switched open and
close. A fitting 16a (e.g. a flare fitting) is attached to one end
of the extension-pipe connection valve 13a. The extension-pipe
connection valve 13b is implemented as a three-way valve capable of
being switched open and close. A service port 14a, which is used
during vacuuming performed prior to filling the refrigerant circuit
40 with refrigerant, is attached to one end of the extension-pipe
connection valve 13b. A fitting 16b (e.g. a flare fitting) is
attached to the other end of the extension-pipe connection valve
13b.
A high-temperature, high-pressure gas refrigerant compressed by the
compressor 3 flows through the discharge pipe 12 in both cooling
operation and heating operation. A low-temperature, low-pressure
gas refrigerant or two-phase refrigerant that underwent evaporation
flows through the suction pipe 11 in both cooling operation and
heating operation. A service port 14b with flare fitting, which is
located on the low-pressure side, is connected to the suction pipe
11. A service port 14c with flare fitting, which is located on the
high-pressure side, is connected to the discharge pipe 12. The
service ports 14b and 14c are each used to connect a pressure gauge
to measure operating pressure during a test run conducted at the
time of installation or repair of the air-conditioning
apparatus.
The indoor unit 1 accommodates the load-side heat exchanger 7. The
indoor unit 1 also accommodates the indoor fan 7f that supplies air
to the load-side heat exchanger 7. Rotating the indoor fan 7f
creates a flow of air that passes through the load-side heat
exchanger 7. Depending on the type of the indoor unit 1 used, the
indoor fan 7f to be used is, for example, a centrifugal fan (e.g. a
sirocco fan or a turbo fan), a cross-flow fan, a mixed flow fan, or
an axial fan (e.g. a propeller fan). Although the indoor fan 7f in
the present example is disposed upstream of the load-side heat
exchanger 7 relative to the flow of air created by the indoor fan
7f, the indoor fan 7f may be disposed downstream of the load-side
heat exchanger 7.
Among refrigerant pipes in the indoor unit 1, an indoor pipe 9a on
the gas side is provided with a fitting 15a (e.g. a flare fitting),
which is located at the connection with the extension pipe 10a on
the gas side to connect the extension pipe 10a. Further, among
refrigerant pipes in the indoor unit 1, an indoor pipe 9b on the
liquid side is provided with a fitting 15b (e.g. a flare fitting),
which is located at the connection with the extension pipe 10b on
the liquid side to connect the extension pipe 10b.
The indoor unit 1 is provided with components such as a suction air
temperature sensor 91 that detects the temperature of indoor air
sucked in from the indoor space, a heat exchanger liquid pipe
temperature sensor 92 that detects the temperature of liquid
refrigerant at the location of the load-side heat exchanger 7 that
serves as the inlet during cooling operation (the outlet during
heating operation), and a heat exchanger two-phase pipe temperature
sensor 93 that detects the temperature (evaporating temperature or
condensing temperature) of two-phase refrigerant in the load-side
heat exchanger 7. The suction air temperature sensor 91, the heat
exchanger liquid pipe temperature sensor 92, and the heat exchanger
two-phase pipe temperature sensor 93 each output a detection signal
to a controller 30 that controls the indoor unit 1 or the entire
air-conditioning apparatus.
The controller 30 has a microcomputer including components such as
a CPU, a ROM, a RAM, an I/O port, and a timer. The controller 30 is
capable of communicating data with an operating unit 26 (see FIG.
2). The operating unit 26 receives an operation conducted by the
user, and outputs an operational signal based on the operation to
the controller 30. The controller 30 in the present example
controls the operation of the indoor unit 1 or the entire
air-conditioning apparatus, including operation of the indoor fan
7f, based on information such as an operational signal from the
operating unit 26 or detection signals from various sensors. The
controller 30 may be disposed inside the housing of the indoor unit
1, or may be disposed inside the housing of the outdoor unit 2. The
controller 30 may include an outdoor-unit controller disposed in
the outdoor unit 2, and an indoor-unit controller disposed in the
indoor unit 1 and capable of communicating data with the
outdoor-unit controller.
Next, operation of the refrigerant circuit 40 of the
air-conditioning apparatus will be described. First, cooling
operation will be described. In FIG. 1, solid arrows indicate the
flow of refrigerant in cooling operation. The refrigerant circuit
40 is configured such that, in cooling operation, the flows of
refrigerant are switched by the refrigerant flow switching device 4
as indicated by the solid lines to direct a low-temperature,
low-pressure refrigerant into the load-side heat exchanger 7.
A high-temperature, high-pressure gas refrigerant discharged from
the compressor 3 first flows into the heat source-side heat
exchanger 5 via the refrigerant flow switching device 4. In cooling
operation, the heat source-side heat exchanger 5 acts as a
condenser. That is, the heat source-side heat exchanger 5 exchanges
heat between the refrigerant flowing in the heat source-side heat
exchanger 5, and the outdoor air being supplied by the outdoor fan
5f, and the condensation heat of the refrigerant is rejected to the
outdoor air. This causes the refrigerant entering the heat
source-side heat exchanger 5 to condense into a high-pressure
liquid refrigerant. The high-pressure liquid refrigerant flows into
the pressure reducing device 6 where the refrigerant is reduced in
pressure and changes to a low-pressure, two-phase refrigerant. The
low-pressure, two-phase refrigerant flows into the load-side heat
exchanger 7 of the indoor unit 1 via the extension pipe 10b. In
cooling operation, the load-side heat exchanger 7 acts as an
evaporator. That is, the load-side heat exchanger 7 exchanges heat
between the refrigerant flowing in the load-side heat exchanger 7
and the air (e.g. indoor air) being supplied by the indoor fan 7f,
and the evaporation heat of the refrigerant is received from the
air. This causes the refrigerant entering the load-side heat
exchanger 7 to evaporate into a low-pressure gas refrigerant or
two-phase refrigerant. The air supplied by the indoor fan 7f is
cooled as the refrigerant receives heat from the air. The
low-pressure gas refrigerant or two-phase refrigerant evaporated in
the load-side heat exchanger 7 is sucked into the compressor 3 via
the extension pipe 10a and the refrigerant flow switching device 4.
The refrigerant sucked into the compressor 3 is compressed into a
high-temperature, high-pressure gas refrigerant. The above cycle is
repeated in cooling operation.
Next, heating operation will be described. In FIG. 1, dotted arrows
indicate the flow of refrigerant in heating operation. The
refrigerant circuit 40 is configured such that, in heating
operation, the flows of refrigerant are switched by the refrigerant
flow switching device 4 as indicated by the dotted lines to direct
a high-temperature, high-pressure refrigerant into the load-side
heat exchanger 7. In heating operation, refrigerant flows in a
direction opposite to the direction in which refrigerant flows in
cooling operation, with the load-side heat exchanger 7 acting as a
condenser. That is, the load-side heat exchanger 7 exchanges heat
between the refrigerant flowing in the load-side heat exchanger 7,
and the air being supplied by the indoor fan 7f and the
condensation heat of the refrigerant is rejected to the air. The
air supplied by the indoor fan 7f is thus heated as the refrigerant
rejects heat to the air.
FIG. 2 is a front view of the indoor unit 1 of the air-conditioning
apparatus according to Embodiment 1, illustrating the external
appearance of the indoor unit 1. FIG. 3 is a front view of the
indoor unit 1 of the air-conditioning apparatus according to
Embodiment 1, schematically illustrating the internal structure of
the indoor unit 1. FIG. 4 is a side view of the indoor unit 1 of
the air-conditioning apparatus according to Embodiment 1,
schematically illustrating the internal structure of the indoor
unit 1. The left-hand side in FIG. 4 represents the front side
(closer to the indoor space) of the indoor unit 1. Embodiment 1
uses, as an example of the indoor unit 1, the indoor unit 1 of a
floor-standing type installed on the floor surface of the indoor
space that is the space to be air-conditioned. In general, the
positional relationship of components (e.g. their vertical
positional relationship) in the following description will be based
on those when the indoor unit 1 is installed in a ready-to-use
state.
As illustrated in FIGS. 2 to 4, the indoor unit 1 includes a
housing 111 having the shape of a vertically elongated cuboid. An
air inlet 112 for sucking indoor air is located in a lower portion
of the front face of the housing 111. The air inlet 112 in the
present example is disposed below the vertically central portion of
the housing 111 and near the floor surface. An air outlet 113 for
blowing out the air sucked in through the air inlet 112 is located
in an upper portion of the front face of the housing 111, that is,
at a position higher than the air inlet 112 (e.g. above the
vertically central portion of the housing 111). An air passage 81
is provided inside the housing 111 to allow air to flow from the
air inlet 112 toward the air outlet 113. The load-side heat
exchanger 7 is disposed in the air passage 81.
The operating unit 26 is disposed at a position on the front face
of the housing 111 above the air inlet 112 and below the air outlet
113. The operating unit 26 is connected to the controller 30 via a
communication line. The operating unit 26 and the controller 30 are
thus capable of communicating data with each other. The operating
unit 26 is operated by the user to perform operations such as
starting and ending the operation of the air-conditioning
apparatus, switching of operation modes, and setting of a present
temperature and a preset air volume. The operating unit 26 may be
provided with a component serving as an informing unit to provide
information to the user, such as a display or an audio output
unit.
The housing 111 is in the form of a hollow box. The front face of
the housing 111 has a front opening. The housing 111 includes a
first front panel 114a, a second front panel 114b, and a third
front panel 114c, which are each attached to the front opening so
as to be detachable. Each of the first front panel 114a, the second
front panel 114b, and the third front panel 114c has a
substantially rectangular, flat outer shape. The first front panel
114a is attached to a lower portion of the front opening of the
housing 111 so as to be detachable. The first front panel 114a is
provided with the air inlet 112. The second front panel 114b is
disposed above and closer to the first front panel 114a, and
attached to the vertically central portion of the front opening of
the housing 111 so as to be detachable. The second front panel 114b
is provided with the operating unit 26. The third front panel 114c
is disposed above and closer to the second front panel 114b, and
attached to an upper portion of the front opening of the housing
111 so as to be detachable. The third front panel 114c is provided
with the air outlet 113.
The internal space of the housing 111 is roughly divided into a
lower space 115a serving as an air-sending portion, and an upper
space 115b located above the lower space 115a and serving as a heat
exchange portion. The lower space 115a and the upper space 115b are
separated from each other by a partition unit 20. The partition
unit 20 has the shape of, for example, a flat plate, and is
oriented substantially horizontally. The partition unit 20 is
provided with at least an air passage opening 20a, which serves as
an air passage between the lower space 115a and the upper space
115b. The lower space 115a is exposed to the front side when the
first front panel 114a is detached from the housing 111. The upper
space 115b is exposed to the front side when the second front panel
114b and the third front panel 114c are detached from the housing
111. That is, the partition unit 20 is placed at substantially the
same height as the upper end of the first front panel 114a or the
lower end of the second front panel 114b. The partition unit 20 may
be formed integrally with a fan casing 108 described later, may be
formed integrally with a drain pan 21 described later, or may be
formed as a component separate from the fan casing 108 and the
drain pan 21.
The indoor fan 7f is disposed in the lower space 115a to create, in
the air passage 81 within the housing 111, a flow of air that
travels toward the air outlet 113 from the air inlet 112. The
indoor fan 7f in the present example is a sirocco fan including a
motor (not illustrated), and an impeller 107 connected to the
output shaft of the motor and having a plurality of blades arranged
circumferentially at equal intervals, for example. The impeller 107
is disposed such that its rotational axis is substantially parallel
to the direction of the depth of the housing 111. The motor used
for the indoor fan 7f is a non-brush type motor (e.g. an induction
motor or a DC brushless motor). This ensures that sparking does not
occur when the indoor fan 7f rotates.
The impeller 107 of the indoor fan 7f is accommodated in the fan
casing 108 having a spiral shape. The fan casing 108 is formed as a
component separate from the housing 111, for example. An air inlet
opening 108b for sucking the indoor air into the fan casing 108 via
the air inlet 112 is located in the vicinity of the center of the
spiral of the fan casing 108. The air inlet opening 108b is
positioned so as to face the air inlet 112 with a predetermined
space therebetween. Further, an air outlet opening 108a for blowing
out the air to be sent is located in the direction of the tangent
to the spiral of the fan casing 108. The air outlet opening 108a is
directed upward, and connected to the upper space 115b via the air
passage opening 20a of the partition unit 20. In other words, the
air outlet opening 108a communicates with the upper space 115b via
the air passage opening 20a. The open end of the air outlet opening
108a and the open end of the air passage opening 20a may be
directly connected with each other, or may be indirectly connected
with each other via a component such as a duct element.
For example, a microcomputer constituting the controller 30, and an
electrical component box 25 configured to accommodate components
such as various electrical components and a board are disposed in
the lower space 115a.
The upper space 115b is located downstream of the lower space 115a
relative to the flow of air created by the indoor fan 7f. The
load-side heat exchanger 7 is disposed in the air passage 81 within
the upper space 115b. The drain pan 21 is disposed below the
load-side heat exchanger 7 to receive condensed water condensed on
the surface of the load-side heat exchanger 7. The drain pan 21 may
be formed as a portion of the partition unit 20, or may be formed
as a component separate from the partition unit 20 and disposed
over the partition unit 20.
The indoor pipes 9a and 9b connected to the load-side heat
exchanger 7 penetrate the partition unit 20 and are extended
downward from the upper space 115b to the lower space 115a. The
indoor pipe 9a is connected to the extension pipe 10a via the
fitting 15a. The indoor pipe 9b is connected to the extension pipe
10b via the fitting 15b. The fittings 15a and 15b are disposed in
the lower space 115a. Refrigerant pipes such as the indoor pipes 9a
and 9b, the extension pipes 10a and 10b, and the fittings 15a and
15b are disposed inside the housing 111 of the indoor unit 1 beside
(on the right-hand side in the front view of FIG. 3) the air
passage 81. That is, within the housing 111, an installation space
202 in which these refrigerant pipes are installed, and the air
passage 81 are arranged in parallel to each other in substantially
the lateral direction.
A refrigerant detection unit 99 is disposed below the air inlet 112
and the air passage 81 (e.g. near the bottom portion of the lower
space 115a) to detect leakage of refrigerant. The refrigerant
detection unit 99 is configured to, for example, detect the
concentration of refrigerant in the air around the refrigerant
detection unit 99, and output a detection signal to the controller
30. Based on the detection signal from the refrigerant detection
unit 99, the controller 30 determines whether a refrigerant leak is
present. As the refrigerant detection unit 99, for example, a
semiconductor gas sensor or a hot-wire semiconductor gas sensor may
be used.
With respect to the lateral direction of the indoor unit 1, the
refrigerant detection unit 99 is located opposite (on the left-hand
side in the front view of FIG. 3) to the area where refrigerant
pipes such as the indoor pipes 9a and 9b, the extension pipes 10a
and 10b, and the fittings 15a and 15b are placed. This ensures easy
handling of the extension pipes 10a and 10b. The fittings 15a and
15b, and the pipes around the fittings 15a and 15b are covered by a
heat insulation material after the indoor pipes 9a and 9b and the
extension pipes 10a and 10b are connected by the installation
contractor who installs the indoor unit 1. At this time, depending
on the operating accuracy with which the heat insulation material
is attached by the installation contractor, a gap may be formed in
the heat insulation material, causing formation of condensation on
the fittings 15a and 15b and on the pipes around the fittings 15a
and 15b. Positioning the refrigerant detection unit 99 as described
above ensures that water does not drip to the refrigerant detection
unit 99 even when condensation forms on the fittings 15a and 15b
and on the pipes around the fittings 15a and 15b.
The refrigerant detection unit 99 is disposed, for example, at a
position below refrigerant pipes such as the indoor pipes 9a and
9b, the extension pipes 10a and 10b, and the fittings 15a and 15b.
In the indoor unit 1, it is highly possible that refrigerant leaks
occur in these refrigerant pipes. Accordingly, for cases where a
refrigerant having a density greater than air under atmospheric
pressure is used, disposing the refrigerant detection unit 99 at a
position below refrigerant pipes such as the indoor pipes 9a and
9b, the extension pipes 10a and 10b, and the fittings 15a and 15b
allows for more reliable detection of refrigerant leakage. In
Embodiment 1, the refrigerant detection unit 99 is disposed in the
lower space 115a within a height range equal to or lower than the
height of a lower opening end 112a of the air inlet 112 and equal
to or higher than the height of a bottom portion 111a of the
housing 111 (see FIG. 4). At the bottom of the lower space 115a, a
small-volume recess that opens upward is provided within the
above-mentioned height range. If a refrigerant having a density
greater than air under atmospheric pressure is used, a very small
portion of leaked refrigerant stagnates in the recess without
escaping out of the housing 111. Therefore, disposing the
refrigerant detection unit 99 inside the recess ensures that
refrigerant leakage can be detected with enhanced reliability.
Since only a very small amount of refrigerant stagnates in the
recess, and no ignition source is present in the recess, there is
no potential risk of ignition.
Inside the housing 111, the air passage 81 and an installation
space 201 for the refrigerant detection unit 99 are adjacent to
each other in a substantially vertical direction. The air passage
81, and the installation space 201 for the refrigerant detection
unit 99 are separated from each other by a first partition plate
200. The first partition plate 200 in the present example separates
the following two spaces from each other a space within the air
passage 81 located between the air inlet 112 and the fan casing
108; and the installation space 201 for the refrigerant detection
unit 99 (see FIG. 4). The first partition plate 200 is formed of a
sheet metal element bent in an L-shape in cross-section. At least a
portion of the first partition plate 200 is placed substantially
horizontally, at a height equal to or lower than the height of the
lower opening end 112a of the air inlet 112. Desirably, the first
partition plate 200 is shaped to have a flow-rectifying effect to
prevent, for example, separation of airflow in the air passage 81
or generation of a vortex in airflow. From the viewpoint of
reducing pressure loss in the air passage 81, the first partition
plate 200 is desirably installed such that the number of bends in
the air passage 8 is minimized.
In Embodiment 1, the first partition plate 200 does not extend to
the installation space 202 in which refrigerant pipes such as the
indoor pipes 9a and 9b, the extension pipes 10a and 10b, and the
fittings 15a and 15b are installed (see FIG. 3). That is, the first
partition plate 200 is not provided directly below refrigerant
pipes such as the indoor pipes 9a and 9b, the extension pipes 10a
and 10b, and the fittings 15a and 15b. Consequently, when
refrigerant leaks out of these refrigerant pipes, the leaked
refrigerant flows down to the installation space 201 for the
refrigerant detection unit 99 without being obstructed by the first
partition plate 200. This allows for more reliable detection of
refrigerant leakage by the refrigerant detection unit 99. It is
highly possible that refrigerant leaks occur easily in the fittings
15a and 15b in these refrigerant pipes. For this reason, it is
desirable that the first partition plate 200 be not disposed at
least directly below the fittings 15a and 15b. This configuration
makes it possible to provide a path along which leaked refrigerant
travels from a leak site to the installation space 201 for the
refrigerant detection unit 99, while allowing the air passage 81
and the installation space 201 for the refrigerant detection unit
99 to be separated from each other by the first partition plate
200.
Next, operation of the indoor unit 1 will be described. Upon
driving the indoor fan 7f, indoor air is sucked in through the air
inlet 112. The sucked indoor air passes through the load-side heat
exchanger 7 disposed in the air passage 81, and turns into
conditioned air, which is then blown indoors from the air outlet
113.
When the indoor fan 7f is in operation, even if refrigerant leaks
out of the indoor unit 1, the leaked refrigerant is blown out from
the air outlet 113 together with air, thus allowing dispersion of
the leaked refrigerant in the indoor space. This helps prevent
localized increases in indoor refrigerant concentration. This
ensures that formation of flammable concentration regions in the
indoor space is prevented even if a flammable refrigerant is
used.
It is to be noted, however, that when the indoor fan 7f is in
operation, in particular, foreign gas (gas other than refrigerant
gas) such as propane or insecticide may be sucked in through the
air inlet 112 together with indoor air in some cases. If this
foreign gas enters the installation space 201 for the refrigerant
detection unit 99, this can cause false detection of the foreign
gas by the refrigerant detection unit 99, with the result that
refrigerant leakage is determined to be occurring even through no
such refrigerant leakage is actually occurring.
In this regard, the air passage 81 and the installation space 201
for the refrigerant detection unit 99 are separated from each other
by the first partition plate 200 in Embodiment 1. This
configuration ensures that foreign gas sucked in through the air
inlet 112 does not enter the installation space 201 for the
refrigerant detection unit 99. This makes it possible to prevent
false detection of the foreign gas by the refrigerant detection
unit 99.
By contrast, when the indoor fan 7f is in stopped condition, if
refrigerant leaks out of the indoor unit 1, the leaked refrigerant
accumulates in a lower area within the housing 111 or near the
floor in the indoor space. This may lead to localized increases in
indoor refrigerant concentration. For this reason, reliable
detection of refrigerant leakage is required especially when the
indoor fan 7f is in stopped condition.
In Embodiment 1, if refrigerant leakage occurs in refrigerant pipes
such as the indoor pipes 9a and 9b, the extension pipes 10a and
10b, and the fittings 15a and 15b, the leaked refrigerant flows
down to the installation space 201 for the refrigerant detection
unit 99 without being obstructed by the first partition plate 200.
This allows for more reliable detection of refrigerant leakage by
the refrigerant detection unit 99. For example, the controller 30
starts the operation of the indoor fan 7f upon detecting
refrigerant leakage based on a detection signal from the
refrigerant detection unit 99. Consequently, the leaked refrigerant
can be dispersed, thus minimizing localized increases in indoor
refrigerant concentration. This makes it possible to prevent
formation of flammable concentration regions in the indoor space
even if a flammable refrigerant is used. Alternatively or
additionally, the controller 30 may, in response to detection of
refrigerant leakage, inform the user that refrigerant is leaking,
by means of a display, an audio output unit, or other such
components provided to the operating unit 26. Further, the
controller 30 may, in response to detection of refrigerant leakage,
forcibly deactivate the compressor 3 or disable activation of the
compressor 3.
As described above, the air-conditioning apparatus according to
Embodiment 1 includes the refrigerant circuit 40 in which
refrigerant is circulated, and the indoor unit 1 configured to
accommodate the load-side heat exchanger 7 of the refrigerant
circuit 40. The indoor unit 1 includes the air outlet 113 provided
in the housing 111, the air inlet 112 provided in the housing 111
below the air outlet 113, the air passage 81 that extends between
the air inlet 112 and the air outlet 113 via the load-side heat
exchanger 7, the refrigerant detection unit 99 disposed below the
air inlet 112, and the first partition plate 200 that separates the
air passage 81 from the installation space 201 for the refrigerant
detection unit 99.
Due to this configuration, the presence of the first partition
plate 200 prevents foreign gas sucked in through the air inlet 112
from flowing into the installation space 201 for the refrigerant
detection unit 99. This makes it possible to prevent false
detection of foreign gas other than refrigerant by the refrigerant
detection unit 99.
With the air-conditioning apparatus according to Embodiment 1, the
indoor unit 1 further includes the fan casing 108 configured to
accommodate the indoor fan 7f. The air inlet opening 108b of the
fan casing 108 is positioned so as to face the air inlet 112. The
first partition plate 200 separates a space within the air passage
81 between the air inlet 112 and the fan casing 108 from the
installation space 201 for the refrigerant detection unit 99.
Foreign gas sucked in through the air inlet 112 tends to flow into
the installation space 201 for the refrigerant detection unit 99
from the space between the air inlet 112 and the fan casing 108.
According to the above-mentioned configuration, the space between
the air inlet 112 and the fan casing 108 and the installation space
201 for the refrigerant detection unit 99 are separated from each
other by the first partition plate 200, thus preventing entry of
foreign gas into the installation space 201 for the refrigerant
detection unit 99 more reliably. This makes it possible to prevent
false detection of foreign gas other than refrigerant by the
refrigerant detection unit 99.
With the air-conditioning apparatus according to Embodiment 1, a
refrigerant pipe (e.g. the indoor pipe 9a or 9b, the extension pipe
10a or 10b, or the fitting 15a or 15b) connected to the load-side
heat exchanger 7 is disposed inside the housing 111 beside the air
passage 81. The first partition plate 200 is not provided directly
below the refrigerant pipe.
Due to the above-mentioned configuration, if refrigerant leaks out
of such a refrigerant pipe, the leaked refrigerant flows down to
the installation space 201 for the refrigerant detection unit 99
without being obstructed by the first partition plate 200. This
allows for more reliable detection of refrigerant leakage by the
refrigerant detection unit 99.
Embodiment 2
An air-conditioning apparatus according to Embodiment 2 of the
present invention will be described below. FIG. 5 is a side view of
the indoor unit 1 of the air-conditioning apparatus according to
Embodiment 2, schematically illustrating the internal structure of
the indoor unit 1. As illustrated in FIG. 5, in Embodiment 2, a
particulate adsorbing element 210 for adsorbing foreign gas is
disposed on a surface of the first partition plate 200 located
closer to the air passage 81. The particulate adsorbing element 210
is made of, for example, a porous material such as activated carbon
or silica gel. Due to the presence of the particulate adsorbing
element 210 on the surface of the first partition plate 200 located
adjacent to the air passage 81, foreign gas sucked in through the
air inlet 112 is adsorbed by the particulate adsorbing element 210
before flowing into the installation space 201 for the refrigerant
detection unit 99. This means that the foreign gas hardly reaches
the installation space 201 for the refrigerant detection unit 99,
thus further reducing the risk of the foreign gas being falsely
detected by the refrigerant detection unit 99.
In some cases, the particulate adsorbing element 210 may adsorb not
only foreign gas but also refrigerant gas. The presence of the
particulate adsorbing element 210, however, does not affect the
accuracy of refrigerant leakage detection. The reason therefor is
as follows.
If R32 is used as refrigerant, the refrigerant concentration
threshold used in determining whether a refrigerant leak is present
is, for example, about 3.6 wt %, which is equivalent to 1/4 of the
LFL (14.4 vol %) for R32, that is, in the order of several percent.
By contrast, the concentration of foreign gas (e.g. butane or
propane) is typically in the order of about 100 to 1000 ppm (0.01
to 0.1%), which is lower by one or more digits than the refrigerant
concentration threshold. Therefore, even if foreign gas and
refrigerant gas are adsorbed by the particulate adsorbing element
210 at such an adsorption rate that prevents false detection of
foreign gas, this does not affect the accuracy of refrigerant
leakage detection.
As described above, with the air-conditioning apparatus according
to Embodiment 2, the particulate adsorbing element 210 is disposed
on a surface of the first partition plate 200 located closer to the
air passage 81.
Due to the above-mentioned configuration, foreign gas sucked in
through the air inlet 112 is adsorbed by the particulate adsorbing
element 210 before flowing into the installation space 201 for the
refrigerant detection unit 99. This helps further reduction of the
risk of false detection of foreign gas by the refrigerant detection
unit 99.
Embodiment 3
An air-conditioning apparatus according to Embodiment 3 of the
present invention will be described below. FIG. 6 is a front view
of the indoor unit 1 of the air-conditioning apparatus according to
Embodiment 3, schematically illustrating the internal structure of
the indoor unit 1. As illustrated in FIG. 6, in Embodiment 3, a
second partition plate 203 is further provided to separate the air
passage 81 from the installation space 202 for refrigerant pipes,
in addition to the first partition plate 200 that separates the air
passage 81 from the installation space 201 for the refrigerant
detection unit 99. The second partition plate 203 is disposed
between the following spaces: a space within the air passage 81
located between the air inlet 112 and the fan casing 108 and the
installation space 202 for refrigerant pipes. The second partition
plate 203 is disposed perpendicular to the first partition plate
200 and in parallel to the lateral surface of the housing 111.
Within the lower space 115a of the housing 111, the second
partition plate 203 in the present example extends vertically from
the height at which the first partition plate 200 is installed to
the height at which the partition unit 20 is installed. The second
partition plate 203 may be formed integrally with the first
partition plate 200, or may be a component separate from the first
partition plate 200. Due to the presence of the second partition
plate 203, the air passage 81 and the installation space 202 for
refrigerant pipes can be separated from each other inside the
housing 111. This makes it possible to prevent foreign gas sucked
in through the air inlet 112 from flowing into the installation
space 201 for the refrigerant detection unit 99 via the
installation space 202 for refrigerant pipes.
As described above, with the air-conditioning apparatus according
to Embodiment 3, the indoor unit 1 further includes the second
partition plate 203 configured to separate between the air passage
81 and the installation space 202 for refrigerant pipes.
According to the above-mentioned configuration, the air passage 81
and the installation space 202 for refrigerant pipes can be
separated from each other, thus preventing foreign gas sucked in
through the air inlet 112 from flowing into the installation space
201 for the refrigerant detection unit 99 via the installation
space 202 for refrigerant pipes. This ensures that false detection
of foreign gas other than refrigerant by the refrigerant detection
unit 99 can be prevented more reliably.
The present invention is not limited to the above embodiments, and
various modifications are possible.
For example, although the above embodiments are directed to a case
in which the indoor unit 1 is of a floor-standing type, the present
invention is also applicable to other types of indoor units, such
as ceiling cassette type, ceiling concealed type, ceiling suspended
type, and wall-mounted type indoor units.
The above-mentioned embodiments and modifications may be
implemented in combination with each other.
REFERENCE SIGNS LIST
1 indoor unit 2 outdoor unit 3 compressor 4 refrigerant flow
switching device 5 heat source-side heat exchanger 5f outdoor fan 6
pressure reducing device 7 load-side heat exchanger 7f indoor fan
9a, 9b indoor pipe 10a, 10b extension pipe 11 suction pipe 12
discharge pipe 13a, 13b extension-pipe connection valve 14a, 14b,
14c service port 15a, 15b, 16a, 16b fitting 20 partition unit 20a
air passage opening 21 drain pan 25 electrical component box 26
operating unit 30 controller 40 refrigerant circuit 81 air passage
91 suction air temperature sensor 92 heat exchanger liquid pipe
temperature sensor 93 heat exchanger two-phase pipe temperature
sensor 99 refrigerant detection unit 107 impeller 108 fan casing
108a air outlet opening 108b air inlet opening 111 housing 111a
bottom portion 112 air inlet 112a lower open end 113 air outlet
114a first front panel 114b second front panel 114c third front
panel 115a lower space 115b upper space 200 first partition plate
201, 202 installation space 203 second partition plate 210
particulate adsorbing element
* * * * *